| 摘要 |
PROBLEM TO BE SOLVED: To obtain a non-volatile semiconductor memory wherein its writing time is shortened and the absolute value of its operating voltage is reduced when erasing it. SOLUTION: The writing method of the non-volatile semiconductor memory has a step (a) for setting the voltage of a p-type silicon substrate 1 to a ground level; a step (b) for setting a control gate 109 to a high voltage Vp1; and a step (c) for giving 0 V to an access gate line of all access gates 7a connected therewith to set to 0 V all the access gates 7a(n-4) to 7a(n+3). Thereafter, when setting the threshold voltage of each memory transistor MT(n) to its writing state, by setting each N<+> diffusion region 5(n) to 0 V in the step (d) following the steps (a)-(c), electrons are tunnel-injected into each floating gate 3a(n) of each memory transistor MT(n) without receiving influence from adjacent memory transistors to set its voltage to a high threshold voltage Vthp.
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